Atomistic insight into the interactions of small molecules with PuO2 surfaces

The safe long-term storage of spent nuclear fuel is of paramount importance. Crucial to this is understanding the interactions between absorbed gases and water with the surfaces of PuO₂. During the long-term storage of spent fuel, canister failure and water ingress are significant concerns, as these can lead to radiolysis and the generation of reactive species and a complex regime of competing chemistries and/or to pressurisation of storage canisters. This project will use atomistic modelling with density-functional theory (DFT) to explore the chemistry at the surface of PuO₂. Modelling will be used to elucidate the nature of the interactions of small molecules at the plutonia surfaces and to predict how these might evolve with ageing under different storage conditions. As part of this, a library of reference simulated infrared (IR) and Raman spectra will be created that can be used to characterise and follow surface speciation in situ and correlate it to environmental conditions. Together, this work will help to address the challenge of finding the most suitable conditions for safe, long-term storage of nuclear waste and to develop mitigation strategies against any issues that storage conditions may produce.

The student will obtain comprehensive training in materials modelling and gain practical experience of a range of techniques including modelling surfaces, performing structural-dynamics calculations to predict vibrational spectra and derive temperature-dependent properties such as free energies, and modelling phase diagrams and particle morphology. These topics are at the forefront of modern materials modelling, particularly applied to actinide materials, and have considerable potential for elucidating the fundamental properties of complex materials. Through the SATURN CDT the student will acquire complementary detailed knowledge of the nuclear fuel cycle and the wider nuclear industry and gain important non-technical skills in research integrity, EDI, time management, teamwork, and presentation skills, among others.

Applicants should have, or expect to achieve, at least a 2.1 honours degree or a master’s (or equivalent) in a relevant science or engineering related discipline.

This project is with the SATURN CDT, and applicants should familiarise themselves with the CDT programme before deciding whether or not to apply. Further details can be found at the CDT website: https://www.saturn-nuclear-cdt.manchester.ac.uk/

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